The present invention relates to a paging receiver having a capability of receiving message data.
The recent development in the electronics art has accelerated the trend toward a miniature and high performance paging receiver. Indeed, a paging receiver which is furnished not only with a simple paging function but also with a message data receiving function is presently on the market and extensively used in the data services industry. Popularization of data services, however, brings about a problem of the supply of valuable information even to those receivers which are delinquent in payment. In the light of this, there has been proposed a paging communication system in U.S. patent application Ser. No. 697,334, U.K. Patent Application No. GB 2 154 347A, and Canadian Patent Application Serial No. 473,573 which are based on Japanese Patent Application No. 59-24337/1984 as filed by NEC Corporation. The paging communication system proposed is configured so that a plurality of receivers are called in group in response to a paging signal transmitted from a base station. The base station transmits to an individual receiver a control signal adapted to inhibit the receipt of message data or cancel the inhibition. The control is added to a paging number particular to the receiver while the message data in question is transmitted after a calling number (common address number) that is meant for many and unspecified receivers.
However, such a system has a drawback that once a battery or like power source installed in the receiver is removed, the inhibition of the receipt of the message data is cancelled allowing even a receiver in delinquency to receive message data again. Further, the prior art system is susceptible to noise because a detection pulse adapted for the inhibition of the receipt of message data and the cancellation of the inhibition is implemented with only a single bit, i.e., logical ONE or ZERO.